Metal bending and stretching apparatus



Jan. 11, 1949. ,1. s. NIELSEN 2,459,132

METAL BENDING AND STRE'I C HING APPARATUS Filed June 7, 1943 I :s sheets-Sheet /Oa, l v

i SI /2w J- S. NIELSEN METAL BENDING AND STRETCHING APPARATUS Jan. 11, 1949;

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Jzmeq; 5. lV/e/sen Jan. 11, 1949.

J. 5. NIELSEN METAL BENDING AND STRETCHING APPARATUS Filed June 7, 194s 3 sheeishe i 3 James 5. N/e/sen wow,

Patented Jan. 11, 1949 UNITED I METAL BENDING AND $TRETCHING APPARATUS aiam'es S. Nilse'nystow, Ohio, assignor to Goodyear Aircraft Corporation, Akron, 011i), a corporation of Delaware Application June 7, 1943,'S1"ial N0. 189;911

3 Claims. 1

This invention relates to metal'workin'g-apparators, and, more particularly, is concerned 'with apparatus of this type for bending 'metal and simultaneously giving the metal a controlled stretch.

It is the general object of the invention to provide improved apparatus for bending metal sheets or lengths and for simultaneously giving an. accurately controlled stretch to the metal being worked.

Another object of the invention is to provide relatively inexpensive, easily handled and operated, long wearing apparatus of the character described which is adapted to production operations, and which can lee-employed to give "a controlled stretching to metal during bending operation thereon.

Another object of the invention is the provision of apparatus including exactly controlled vand positioned work clamping jaws .Eor supporting the metal to be worked, and including-means for effecting relative movement between the work and a die to achieve a controlled bending and stretching of the worl; around the die.

Another object of the invention is to provide metal bending and stretching apparatus including pivotally mounted work'engagingjaws which are free'to follow and align themselves. I

The foregoing and other objects of theinven- 'tion are achieved by theprovision of apparatus including a die, means supporting the die, means for gripping opposed portions of 'a -length of metal, means for eifecting relative'mov'em'nt be- "tween the die supporting means and -the "'m'tal gripping means tobend'thelengthdf iritalaboiit the die, and'mean's for'positivly controlling the position of the metalgripping means "to 'apply 'a controlled stretching to'the lehg'thofinet'al during the bendingoperation.

For a better understanding of the invention,

reference should 'behad 'to the accompanyin drawings wherein Figure 1 'dia'grainrhatically illustrates in side elevation one embodiment of apparatus incorporating the principles of the invention; and Figures 2 to 6 are all similar to Figure 1 but show other enibodiments "of the invention. I

. In the drawings, and having -particular ref.-

Ierenceto Figure '1, thenunieral 'H'Iindicatesg'en- M 'rally a'sui'table'bas'ewhich centrally supports-a 0 "hydraulic cylinder or'c linders [2, "or other suit-'- able means, for example '"afscrew or toggle mean;- anism adapted to move a die supporting table -4 toward'or fromth'e 'ba'se "Hi. Thedie table 1 movably carries a die l s whidh isfadaptedto be engaged laterally against a length onshee't pr metal M comprising the material to be formed over the die. 7 I

The metal M is gripped at its ends in suitable jaw means I 8 each mounted on'a turnbufclle 2p "in turn pivotally secured, =as at-22, to "portions of the fram'elll.

In the operation of this embodiment of the invention the metal M is mounted between the jaws I8 and the -turnbu'ck1es '20 are'tig'htened to give a controlled stretch to the metal. There'- after, 'or simultaneously with the s'tretchingrdf the metal M, the hydraulic cylinder or cylinders form metal lengths with 'relativelywide he go 4 portions. In operations of this type it is erally advisable to impart certain a-d'ded stre ch to the metal M by tightening the-turnbuclrl'es if!) during the movement of thedie 16 against the metal, with the added stretch insuringtha't the flanges on the metal are free of wrinkles "for buckles. On the other hand, whenthe'me'ta is formed over a "die having a highcrown to'imip'art'a considerable bend to the metal/specifically without the romanc r angea'uis' rten advisable to slack off onth'e turnbucklesj uring the metal "bending and stretching opera on because the considerable movement ofythe dip into the work piece to bend the work piecearounu a large curve of 'shortr'adius imp'artsaconsr able stretch to 'thelnetal, 'This stretch' trolled .by slacking 'ofi on the turnbuckle's a 1:9 give an exactly controlled stretchfto'the 'metal' M during the 'bendingzoperation to ther byp icle a finished work piece having 'a mini spring-backand no wrinkles or louckle over stressed or ruptured. The .p'i'votal e turnbuckle s '20 insures'thatthela w' niernliers Joana anemi buckles 2c are 'ffre'e'to tu tape renew the "niettil The embodiment of the invention illustrated in Figure 2 is identical to that illustrated in Figure 1, with the single exception that the turnbuckles 20 have been replaced by hydraulic cylinders 30 which provide a simplified and more readily actuated control for the jaw members It will be understood that suitable controlnieans are provided in conjunction with each one of the hydraulic cylinders 30 so that the pistons and piston rods of these cylinders which mount the jaws 3 can be moved positively by hydraulic action ,.in,. .either direction to impart further stretch to the metal M' or to slackofi on the application of stretch to the metal. Except for the numerals 30 used to designate the hydraulic cylinders, like numerals have been employed in Figure 2 to designate identical parts shown in Figure 1 except that in Figure 2 the sufiix alias been added to the numerals.

In the form of the invention illustrated in Figure 3, parts identical to those illustrated in Figure 1 have been indicated by like numerals except that the suffix b has been added. In this form of the invention the die Nib is made stationary and the hydraulic cylinders 3% are pivotally connected, as at 2212, with blocks 36 which are slidablysupported for vertical movement in the base Hlb so, as to effectrelative movement between the metal M and the die 46b underthe action of hydraulic cylinders 38 'or other suitable meansfor controlling the position of the blocks a I The embodiment of the invention illustrated in Fig. '4 is like the form of the invention shown in EigureZ except that the fluid pressure cylinders 30c. arepivotally secured, as at 220, to brackets 42. These brackets are made slidable in'beds A l fastenedto the base 190 and each .brackets position on its bed is adjustably fixed bye-threaded spindle id operated by a hand wheel nut 4'3. A two armed lever l8 swingable about a pivot 55 is engagedby the fluid pressure cylinder 30c and connects to the jaw lilo. The machine shows in dottedlines the position of the working .mechanism of the machine and the working materialafter the bending and stretching operation. It" willbe' recognized that'parts Figure 4 identical to portions. of Figure 2 have been indicated by like numerals but with the su'ffixc being added. p

A further embodiment ofv the invention shown in Figure 5, which illustrates in full lines the apparatus in the position with the material shaped around the die and in dotted lines the position of the apparatus before the stretching and bending of the, material. The apparatus of Figure is generally similar to that of Figure 3. However, Figure 5 includes a movable die lBd and has the side cylinders tiid m'ounted on supports fill which. are movable on thebeds 53. Movement ,of the supports, 60 is achieved by means "of fluid pressure cylinders 66, pivotally slecured at one end to the cylinderUiZd having their. piston rods connected to the sup ports 60. ,This arrangement has the advantage of' permitting the bending of bars or sheets to 1morethan half a circle, and the fact that the cylinders 38d and 12d operate in opposite directionsreduces the overall height'of the machine. Like'numerals have been employed in thisfigu re of the drawings to indicate like partsto other figures except that the'suifix d has been added.

Stillanother form of the invention is shown in Fig. '6. The fluid pressure cylinder-51 386 in "this case are adiustably mounted on arms 18 ated by an electric motor (not shown).

a form 86 fastened to the table 16.

Links 84 pivotally attached with their one end to the nut 82 and with their other end to the arms l9 swing the arms toward the beam 18, as showndn the dotted lines when the nut 82 isymoved on 'the spindle. This action bends a work piece M held between the jaws l8e around While the work piece is bent around the form sufficient stretch is imposed on it by the cylinders 30c to keep the material from wrinkling. Parts similar to like parts in the other figures have been indicated in Figure 6 by the same numeral but the suflix e has been added.

It will be recognized that each one of the embodiment-s er the invention illustrated in Figures 2 to :6 functions in a manner generally similar to that above described in conjunction with Figure 1, namely, the metal to be worked is given a controlled bending and stretching operation by effecting relative movement between the die and the jaw members supporting the metal, and with the position of the jaw members being accurately controlled during the bending operation to impart into the metal an exactly controlled stretching whereby all wrinkles and buckles are removed from the metal and spring back is kept to a minimum all without over stressing or rupturing the metal work piece.

Accordingly, the objects of the invention have been achieved by the provision of relatively inexpensive and readily operated apparatus for bending and simultaneously positively stretching a metal work piece in exact and controlled amounts and to desired contours. The improved apparatus is readily adapted to operate on metal workpieces of a wide variety of forms or cross sectionals shapes and contours, and is particularly adapted to operations upon metal pieces having large flange portions or bends on sharp radii where heretofore portions of the metal have been either over stretched or under stretched.

' While in accordance with the patent statutes the invention has been specifically illustrated and described in certain of its best known embodi merits, it should be clearly understood that the invention is not to be limited thereto or thereby, but that the scope of the invention is defined in the appended claims.

What is claimed is:

.1. Metal forming apparatus including a pair of gripping jaws adapted to grip opposite ends of a length of metal to be formed, a die, hydraulic means for moving the die toward and from a metal length gripped between the jaws, mounting means pivotally supporting each jaw for tilting movement toward and from the die, a' hydraulic means associated with each of the mounting means for moving said mounting means in a direction substantially parallel to the direction of movement of the die, and a hydraulic means associated with each mounting means for moving it in a direction at substantially'right angles to the movement of the die.

2. Metal forming apparatus including a bed, a die positioned centrally of the bed, hydraulic means for moving the die substantially vertically with respect to the bed, supports slidably mounted for substantially horizontal movement on the bed on each side of the die, hydraulic means associated with each support for moving it toward or from the die, a block slidably carried for substantially vertical movement on each support, a hydraulic means carried by the support and controlling the vertical position of the block,

and a gripping jaw pivotally secured to each block for tilting movementtoward and from the die.

3. Metal forming apparatus including a bed, a die positioned centrally of the bed, hydraulic means for moving the die substantially vertically with respect to the bed, supports slidably mounted for substantially horizontal movement on the bed on each side of the die, means associated with each support for moving it toward or from the die, a block slidably carried for substantially vertical movement on each support, means carried by the support and controlling the vertical posi- :tion of the block, and a gripping jaw pivotally secured to each block.

JAMES S. NIELSEN.

REFERENCES CITED The following references are of record in the of this patent:

UNITED STATES PATENTS 

